Monitoring activities at these sites (map) were funded jointly by the USGS and a partner
agency through the USGS Cooperative Water Program (http://water.usgs.gov/coop/). Lack of partner funding for
these sites after June 30, 2016 resulted in discontinuation of all
monitoring activities. Questions or concerns can be directed to Kirk
Miller (kmiller@usgs.gov;
307-775-9168) or Wayne Berkas (wrberkas@usgs.gov; 406-457-5903).

Current conditions at selected sites based on the most recent data from on-site automated recording equipment.
Measurements are commonly recorded at a fixed interval of 15- to 60-minutes and transmitted to the USGS every hour.
Values may include "Approved" (quality-assured data that may be published) and/or more recent "Provisional" data
(of unverified accuracy and subject to revision). Most current data are provisional.

The same data accessed by the Current Conditions link above but including both active and discontinued sites
with data for any part of the period October 1, 2007, through the present. Values may include "Approved"
(quality-assured data that may be published) and/or more recent "Provisional" data
(of unverified accuracy and subject to revision).

Summary of all data for each day for the period of record
and may represent the daily mean, median, maximum, minimum, and/or other derived value.
Values may include "Approved" (quality-assured data that may be published) and/or more recent "Provisional" data
(of unverified accuracy and subject to revision).
Example.

Statistics are computed from approved daily mean data at each site.
These links provide summaries of approved historical daily values for daily,
monthly, and annual (water year or calendar year) time periods.

Data from field and/or laboratory analyses of water samples,
biological tissue, sediments, or other environmental samples.
Data include approved, quality-assured data that may be published,
and more recent provisional data, whose accuracy has not been verified.

Introduction

The U.S. Geological Survey's (USGS) National Water Information
System (NWIS) is a comprehensive and distributed application that
supports the acquisition, processing, and long-term storage of water
data. Water Data for the Nation serves as the publicly available portal to a
geographically seamless set of much of the water data maintained
within NWIS
(additional background).

The USGS collects and analyzes chemical, physical, and biological
properties of water, sediment and tissue samples from across the
Nation. The Water Data for the Nation discrete sample data
base is a compilation of over 4.4 million historical water quality
analyses in the USGS district data bases through September 2005. The
discrete sample data is a large and complex set of data that has
been collected by a variety of projects ranging from national
programs to studies in small watersheds. Users should review the help notes and particularly the data
retrieval precautions before beginning any retrieval or analysis
of data from this data set. Additions of more current data,
modifications to ancillary information, and enhanced retrieval
options to help users find and appropriately use the data they need
are planned for a future release of Water Data for the Nation.

At selected surface-water and groundwater sites, the USGS maintains
instruments that continuously record physical and chemical
characteristics of the water including pH, specific conductance,
temperature, dissolved oxygen, and percent dissolved-oxygen
saturation. Supporting data such as air temperature and barometric
pressure are also available at some sites. At sites where this
information is transmitted automatically, data are available from
the current data system.

Once a complete day of readings are received from a site, daily summary data are generated and made
available online. USGS finalizes data at individual sites on a continuous
basis as environmental conditions and hydrologic characteristics permit.